After weeks of debate, federal and other health experts are considering a new recommendation — that all Americans, especially those in areas with high coronavirus infection rates — wear masks when in close contact to others, caregiving, or other activities.  

While high-grade, N95 masks are being reserved for health care workers who are facing severe shortages, homemade masks, and other types that are still available for purchase may – experts now say – offer some protection, though they are not substitute for hand washing or social distancing. They are also helpful in keeping people from spreading the disease.

There’s no research on what fabrics specifically block the coronavirus, but the chart below was created from a study conducted by scientists at the University of Cambridge who were investigating the value of homemade masks for prevention flu during a pandemic by assessing how effectively certain fabrics block small particles such as those that carry a virus.

In their report, the Cambridge research team stressed that homemade masks should be a last resort, but with budgets stressed across the country and mail orders taking weeks, they may be the only option for many.  Here’s what they found about the effective of different fabrics. Directions for making your own follow.

The Best Fabrics for DIY Masks and How to Make Your Own

Making and Using an Effective Mask

If you decide to make a mask, these tutorials will walk you through the process.

l. Doctor shows how to make a maskStep by step guide from a physician

2. Leading craft company Hobby Lobby – face mask making guide

3. Expert tailor instructions – How to Make a Mask – With free pattern.

Safety Insructions

Whether you purchase your mask or choose to make your own, remember that you will only be protecting yourself and others if you use it properly, follow these steps, and watch this World Health Organization tutorial to be sure you know what to do:

• Before putting on a mask, clean hands with alcohol-based hand rub or soap and water.

• Cover mouth and nose with mask and make sure there are no gaps between your face and the mask. (or as close as you can get with a homemade mask).

• Avoid touching the mask while using it; if you do, clean your hands with alcohol-based hand rub or soap and water first.

• Replace the mask with a new one as soon as it is damp and do not re-use single-use masks.

• To remove the mask: remove it from behind (do not touch the front of mask); discard immediately in a closed bin; clean hands with alcohol-based hand rub or soap and water.

• Reusable fabric masks should be washed hot water and soap after each use.

A mask may help you stay healthy, but it should not make you overconfident. Be sure to continue all other forms of coronavirus prevention and protection. Even with the mask, continue social distancing.

Sheree Crute is editor and co-founder of Fierce and a health journalist based in New York.